| 用你喜欢的方法计算下面各题. 450÷18+375 | 3.68-0.82-0.18 | 36×( + ) | ×24-6×![]() |
-( + ) | 8.24-8.24÷4 | 19÷[( + )÷ ] | × ÷ +![]() |
×71+19÷![]() |
=25+375,
=400;
(2)3.68-0.82-0.18,
=3.68-(0.82+0.18),
=3.68-1,
=2.68;
(3)36×(
+
),=36×
+36×
,=8+21,
=29;
(4)
×24-6×
,=
×(24-6),=
×18,=16;
(5)
-(
+
),=
-
-
,=
-
-
,=1-
,=
;(6)8.24-8.24÷4,
=8.24-2.06,
=6.18;
(7)19÷[(
+
)÷
],=19÷[
÷
],=19÷
,=10;
(8)
×
÷
+
,=
×
×
+
,=
×
+
,=
+
,=
;(9)
×71+19÷
,=
×71+19×
,=
×(71+19),=
×90,=63.
分析:(1)先算除法,再算加法;
(2)(5)根据减法的性质简算;
(3)(4)运用乘法分配律简算;
(6)先算除法,再算减法;
(7)先算小括号里面的加法,再算中括号里面的除法,最后算括号外的除法;
(8)先把除法变成乘法,再运用乘法交换律简算,最后算加法;
(9)先把除法变成乘法,再运用乘法分配律简算.
点评:此题是考查四则混合运算,要仔细观察算式的特点,灵活运用一些定律进行简便计算.